Glow plug snapped just below thread - what size tap to thread the plug body?

[julianf]

I dont know for sure if the body ever moved, but all the threaded top is out, with the center wire attached to it - so i now have a hollow plug stuck.

I filled up the recess with plusgas last night, and had a look a few hours later, and there was no noticable change in level, but at least i can leave it like that a while to soak.

My plan is to tap the hollow section, screw in a set screw, with a bolt on its thread, and then work them against each other (and the head) to, i hope, pull out the body of the glow plug.


Ill saw through one of the other plugs to take measurements, but, in the mean time, does anyone know the right tap to use, so as i can order it, and a few either side of that, in preparation?


Thanks

 

[zeaphod]

I'd drill it out to take the closest sized tap I have.

 

[julianf]

ok - its hollow as it is, as the center wire / element (?) has pulled out anyhow - so i just have a tube - no need for me to drill (so long as the tip stays attached!)

 

[Kwakerman]

Can be done see here probably an expensive kit so may be worth asking a garage who has the kit for an estimate, get it wrong and it may be a new head time.

 

[Blackburn]

Can you cover glowplug area over with a piece of carpet or sacking then try turning the engine over to see if the pressure will force it out?

 

[Kwakerman]

Can you cover glowplug area over with a piece of carpet or sacking then try turning the engine over to see if the pressure will force it out?

The body will still be held in by the threads, it will be the top 'nut' section that has sheared off.

 

[wammers]

The body will still be held in by the threads, it will be the top 'nut' section that has sheared off.

That is not the impression i get from the first post. Plus gas down it and running engine should blow it out. He will need to cover it with a rag to catch it.

 

[Kwakerman]

That is not the impression i get from the first post. Plus gas down it and running engine should blow it out. He will need to cover it with a rag to catch it.

Yep just reread it and you are correct